O assemble a piece of furniture, a wood peg must be inserted into a predrilled hole. Suppose that the diameter of a randomly selected peg is a random variable with mean 0.35 in. and standard deviation 0.005 in. and that the diameter of a randomly selected hole is a random variable with mean 0.352 in. and standard deviation 0.004 in. Let x1 denote peg diameter, and let x2 denote hole diameter. Why would the random variable y, defined as y = x_2 - x_1, be of interest to the furniture manufacturer?